Do power cords really matter?

I'm sure this has been discussed ad nauseum in the past, but while reading an ad for a power cord, I've had a very simplistic thought on which I would enjoy hearing other's opinions.
Case in point : The idea of dedicated lines appealed to me, but as we will be moving in the not too distant future, I just grabbed a left over roll of 14-3 Romex and strung about 60 ft. through the basement, and terminated in a box w/ a couple of audio grade duplexes. I did run the ground wire directly outside to a separate ground rod. (I realize for optimum performance I should have several runs to separate amp, digital, analog, etc.) My question is this: am I really to believe the last 6 ft. of power delivery can be that critical, when it has already traveled a much greater distance in ordinary wire. As we use outlets for convenience only, why not just terminate a 6 ft piece of Romex w/ high grade connectors? Are we just buying eye candy? Have we been duped w/ the hype?
Without having studied power conditioners, perhaps they can actually "clean" the raw power electronically?
Thank you for enduring my Sunday morning musings - all opinions cheerfully received.
Best regards,
Tom